Electric lighting.



C. P. STBINMETZ.

ELECTRIC LIGHTING.

APPLICATION FILED APR.30, 1902.

Patented Deo. 5, 19M.

lnvencr: Charles @Senmez (Dnesses:

V.u TED sTaTEs vATEN CHARLES P. lS'IIIN'MIEIJIZ, 0F SCHENECTADY, NEW YORK, .ASSIG-NOR TO GENERAL ELECTBIU COMPANY, A CORPORATION NEVE' YORK. I

ELECTRIC LIGHTING. I

Specification of Letters Patent.i l Paent'ed De, 5, 1911, original application inea April as, woo, serial No. 14,224. .Divisea and this application filed April so;

1902. Serial- No. 105,305.

To all whom tt may concern:

Be it known that I, CHARLES P. STEIN- METz, a citizen of the United States, residing at Schenectady, in the county of Schenectady and State of New York, have invented certain new and useful ,Improvements in Electric Lighting, (division of my prior application, Serial No. 14,224, filed April 25, 1900,) of which the following is a specification. U

'It is well known that there are in existence various devices for transforming the energy of electric current into light, which are superior in eiiiciency to the ordinary incandescent lamp of commerce, but are objectionable in that they require, for one reason'or anotherpextremely high potentials in starting as compared with the potentials necessary tomaintain them in operation. ,Une

lamp of this class is that in which the light.- giving b'ody is composed of what is sometimes called a conductorof the second class, or; asl prefer to call it, a pyro-electrolytic conductor, usually taking the form of a rod of oxid of magnesium or other metal oxid, or compound of metallic oxids. lamp of this type may be designed to run successfully on a single-phase alternating circuit of 100 volts, but requires for its starting a potential which may rise to 500 or 1000 volts,

or higher. By using as light-giving body amixture of initially conducting and' non-conducting substances, as a mixture of ferrite and chromite of iron, Fe3O4 and Cr2FeO4,

as set forth and claimed in .my application Ser. No. 41,350, filed Dec. 28, 1900, this voltage may bereduced, but even with this improvement a starting device is advantageous.

. Another lamp, possessing to a certain extent the same characteristics, is that described in my pendingapplication, Ser. No.v 7265, in which light is formed by the passage of an arc between electrodes vaporizable atv low, temperature, which electrodes f reuently take the form of bodiesV of mercury. In some of the formsshown in said ap lication the mercury electrodes are inclosed in a lassvessel, from which the air has been exausted to such an extent as to reducethe voltage necessary to strike across and start the arcQ but even with the most favorable adjustment of the vacuum I lind it diliicult to start such lamps in .multiple on ordinary,v constant-patentlal circuits 'without the addlv L Y tion of some extraneous starting device, al-

nection with constant-current circuits.

tion, shown certain other lamps possessing the same general characteristics but arthough they are well adapted for use in conranged to start by relative vmovement 'between two electrodes, and-:such lamps are -very suitable for certain classes of work.

i For certain other purposes, however, I find it better to dispense lwith the movement4 be-l tween the electrodes and to start the lamps by. subjecting them to a very high potential.

This is, as has been stated, extremely easy inv connection with series circuits, alternating or d1rect, but dllicult 1n connection :with commercial low-tension, multiple arc or constant potential circuits.

a a a My present invention alms to provide a simple and convenient means for starting, v

on ordinary constant-potential alternating circuits, any lamps which` require higher voltage at startingthan during the running.

condition, whether of the type'described or -of other types. .y v

In the drawings attached to this specification, which'represent various modifications of-my invention, Figurel is a View of a` lamp of the'general character described 1n my application, Ser. No. 7 265, provided'with my improved starting device; Flg. 2 1s a cross-section of a lamp based on the general principle o f the lam-p of Fig, 1, but provided with certain im rovements; Fig. 3 is a View `of an electrolytlc lamp to which my present invention has been applied; and Fig. 4 is an illustrative diagram..4

Referring more particularly to Fig. 1 E4, E5, are terminals between which is maintained a substantially-constant alternating electromotive force, as by connection to the "mains 2 2. From these terminals wires. lead to the terminals E, E7, of the lamp B,l

which lamp consists of two glass tubes joined to a central chamber, as shown, with conducting points fused into the glass at E, ET. A third terminal, entering a depression or cup D4, is provided as shown.v Thelower ends of the tubes D, D",'and the cup D4 are lled-with'mercury,or other suitable substance, as set forth 1n m application'above referred to, and t-he sur ace of the mercury is in each case covered with a thin layer 'of' a color-modifying substance such as a mixturef of anhydrous halogen/salts of earth metals, as iodids of lithium arid sodium, and some neutral-.ordilutant substance asy the terminals E4,y E5, and a connection. is Vmadefrom a common pointV E8 between the ,condenser andthe self-inductionto the een# l10y tral electrode D4. With'theparts arranged as follows,llet us suppose that the switch'is closed and thatalternating current at a potential, for, example, -of 1 00 volts be allowed to passvto the terminals, the vacuum 4in. theflamp4 being supposed to be such .as to produce the' minimum dielectricV strength,. as for example, l mm. on the ordinary mercury gage.-

and E?, E5, are the sides, and-if the. ohmic resistance of the self-induction coil 5,' and ,the energy l'ost'in 'the condenser 4, are com-y paratively small, the voltages E4, E5, and E8, 2 5 E5, may eachof them bevery many times the magnitude of the resultant 'voltagesE E5.

., In the theoretric'al extreme case the voltage' across E4, Esfwould lag the voltage E4, E5 by 90 degrees, and the voltage E5, E5, would lea`d -the voltage E4, E5, by 90 degrees, as

Ishown in Fig. 4 in dottedvlin'es, so that the ,phase triangle would be one of infinite alti-` tude,and the voltages E4, E8, would be innite-- In practice this condition. cannot occur, butthese voltages may be ten times the impressed voltage, or'even higher.I This being the case, it w1ll be seen that that portion of the tube between the left-hand ter` minal D5 andthe central terminal D4 will be 40,exposed to the total voltageacross the condepser 4, while vthe right-hand portionofA vthe tube will -beexposed to the total voltage across the .selinduction'5, so thatalthough' the total voltage across the'tube maybe only 100, yet the volt-age across each half of the,

tube may exceed 1000. This high voltage will eausetheair', hydro en, or other 'rarelied gas Jin one or both sides of the tube to' ybreak down, and an arc will be started from 150v the left-hand terminal D to the centralv terwhole tube is warmed land filled with conducting vapors. This arc is formed. of' fa column of'mercury vapor evaporated from the terminals, and mixed with this mercury vapor are the halogen salts above mentioned,

as, fon example, lithium iodid. The mer- Jeuryarc 'ves a ybright light, at high elfi.-y

ciency, an the lithium adds t0 the lightr the red' line which v.is wanting. The lithium would attack the glass envelop and destroy it, but for the. fact than it exists'in `the" yUnder these' circumstances the i voltageE4, E5, will form the base of -a tri- 20 angle,'Fig.v4,' of which the voltages E4, E8.,

ionized state, constantly ready to combine with t-he free iodin, and thus'incapable of combining with the silicious substances forming the walls of the tube. The resultis that a continuous stronglight, which may be white or of-any Vother desired color according to thenature and quantity of the amount of color-modifying substances introduced,

issues continuously from the tube.

The are gradually warms the mercury until it reaches a temperature'nearer the boiling point, when the voltage necessary to maintain the arc becomes v ery` greatly'reduced and-the current flow for -a given voltage correspondingly increases, but as fast as current 'is taken on the left-hand side of the tube, for example, a resistance is introduced in multiple with the condenser, and as -fast as current isv taken on theright-hand 'aside of the lamp'a resistance'is interposed in multiple with the self-induction. The eect of resistance in multiple With a' self-induction or condenser is to decrease its reactive effect, which causes the triangle pf phases to collapse, as itwere, as indicated in Fig. 4* by` the triangle E4 E5 E8. But if for'any cause the arc .should be extinguished on either side of the tube, as might happen, for example, if a very sudden dra-ft of air should cool one of the electrodes, the phase triangle `would extend, the voltagewould rise, and the lamp would automatically start itself.

again. The current is then forced to flow through the lamp under all conditions` and automatically regulated.

It will be seen that my improved starting device is perfectly automatic and instantaneous in lts action, and that it does not require anyv moving parts or .hand regulation.

a U-sl1ape, with a central terminal D4 at the 115 llower part and two condensin 'chambers .The relative values of the reactance of the i G1, "G2, containing the electro es D5, D7.,

which electrodes are annular in shape, as wvell .shown in the drawin supported on a base plate is carried by the' external casing N12, provided withfterminals E4, E5. The tube B is held in place by a protecting plate N1-s With anasbestos vwasher N1? interposed. A

*condenser 4 and a self-induction coil 5 are 125 suspended from the cap N, andl are connectedaccordin to the scheme of connec@ tions Shown in ig. 1.,

The=operation of this lamp will be readily The tube 'B is l s, which in turn 120 understood from what preceded, and .130

l this gure Loups@ further description is, therefore, unnecesi sary. Y

Havingthus described the operation of my invention as ap lied to the lamp shown in my' application er. No. 7265, I will now proceed to describe its application to the pyro-electrol tic lamp shown in Fig. 3. In (g isa rod formed of metallic oxids, either pure or mixed, as is well un'- derstood '1n the art. This rod is carried by a central support 6, and by side supports 7 and 8. The side support 7 is connected to the terminal E, and the side support 8 is connected to the terminal E". The condenser 4 and the self-induction coil 5 are connected in series, and from the common point is taken a lead to the central ost 6. Obviously; the lamp may be suspen ed in an inverted position, and .supplied with a glass globe, as shown in Fig. 2, if so desired. In starting, the rod does not take any substantial amount of current, owing to its very high` resistance, but the voltages acrossthe condenser and self-inductionr1se toa cons iderablevalue, as above explained,

until finally current is forced through the rod.. This action may be aided by external heat, if it is so desired. As soon as current lbegins to flow through the rod the phase 'triangle collapses and the voltages are reduce as shown in Fig. 4. In 4this form 'of lamp, as in the other above described, it is possible for one side to start first, and to reduce the volta e 011 the other side. If 'the rod be long an thick one side only will burn, and the single lamp thus formedis within my present invention, but by making the rod fairly short and thick the active side -will be caused to heat the inactive side,l whereby the whole lamp will be started.-

It is not essential to' have the condenser.

and self-inductioncoil in circuit after the lamp'starts, but the same impedancecombination may be used to start a numberof lamps successively. I prefer however to leave the condenser in circuit, on accountof its 'steadying effect.

What-I, claim as new and desire to secure by Letters Patent of the United States isz-'- a lThe method of operating an electric of paths for current iow, whic consists in deriving from a source of alternating zcura rent a plurality of voltages out of phase with each other and impressing these volt-.`

a plurality;

lili-dil.

ages upon respectively diferent paths 1n said lamp, these voltages coperating to produce flow of current in the lamp.

2. The method 'of operating an electric l lamp having electrodes aiordin a plurality of paths for current flow, whic consists in impressing on at least two of the electrodes the potentials of the'mains of a source of alternating current and upon another electrode a potential intermediate -in value, whereby coperatin Acurrents flow in the lamp between said e ectrodes.

'3. The method of starting and operating an electric apparatus ofcomparatively high resistance at starting, which consists of eX- posin separate portions of the apparatus to vo tages of which the aggregate numerically exceeds t-he voltage of the system from which the apparatus is fed and reducing such Voltage as the current taken by the apparatus lncreases.

4. The method of supplying energyA to a translatingdevice of comparatively high resistance at starting, which consists in supplying separate portions of the device respectively with the individual voltages of impedances of diierent power factor cons nected in series. i

5; The method of Supplying energy from an alternating current source to an electric lamp havin coperatingelectrodes affordinga plura ity of paths for current flow, which consists in exposing said paths to the action of voltages dependent u on the interaction of impedances of di erent power factor, the resonant voltages being automatically reduced when said lamp takes current.

6. The method of starting an electric arc lamp havin cooperating electrodes aclfording a plura ty ofpaths for current flow, which consists in exposing said paths to the action of an abnormally gh voltage dependent upon the interaction of impe ances of different power factor supplied with alternating current, the resonant volta es bein automatically reduced when sai lamp ta. .es current.

In witness whereof I have hereunto set lllitcliesses;j 'Y

BENJAMIN B. HULL, HELEN. Onronu. 

